BACKGROUND: Environmental factors such as nutrition or exposure to infections play a substantial role in the pathogenesis of type 1 diabetes (T1D). We have previously shown that gluten-free, non-purified diet largely prevented diabetes in non-obese diabetic (NOD) mice. In this study we tested hypothesis that early introduction of gluten-enriched (gluten+) diet may increase diabetes incidence in NOD mice. METHODS: Standard, gluten-free, gluten+ modified Altromin diets and hydrolysed-casein-based Pregestimil diet were fed to NOD females and diabetes incidence was followed for 310 days. Insulitis score and numbers of gut mucosal lymphocytes were determined in non-diabetic animals. RESULTS: A significantly lower diabetes incidence (p < 0.0001) was observed in NOD mice fed gluten-free diet (5.9%, n = 34) and Pregestimil diet (10%, n = 30) compared to mice on the standard Altromin diet (60.6%, n = 33). Surprisingly, gluten+ diet also prevented diabetes incidence, even at the level found with the gluten-free diet (p < 0.0001, 5.9%, n = 34). The minority of mice, which developed diabetes on all the three diabetes-protective (gluten+, gluten-free, Pregestimil) diets, did that slightly later compared to those on the standard diet. Lower insulitis score compared to control mice was found in non-diabetic NOD mice on the gluten-free, and to a lesser extent also gluten+ and Pregestimil diets. No substantial differences in the number of CD3(+), TCR-gammadelta(+), and IgA(+) cells in the small intestine were documented. CONCLUSIONS: Gluten+ diet prevents diabetes in NOD mice at the level found with the non-purified gluten-free diet. Possible mechanisms of the enigmatic, dual effect of dietary gluten on the development of T1D are discussed.

Division of Immunology and Gnotobiology Institute of Microbiology Czech Academy of Sciences Prague Czech Republic

References provided by Crossref.org

Gluten-Free Diet Only during Pregnancy Efficiently Prevents Diabetes in NOD Mouse Offspring

Prevention or early cure of type 1 diabetes by intranasal administration of gliadin in NOD mice

The role of gut microbiota (commensal bacteria) and the mucosal barrier in the pathogenesis of inflammatory and autoimmune diseases and cancer: contribution of germ-free and gnotobiotic animal models of human diseases